The present invention relates to a multi-purpose paper clip and, more particularly, to a multi-purpose paper clip that provides significant improvements in performance, as compared with previously known paper clips, and can carry out entirely new functions.
There exist numerous known types of paper clips, most of which are made of a metal wire of round cross-section and with some degree of resiliency that is bent into various shapes to produce two branches, which are bendable simultaneously in opposite directions such that one branch engages the top sheet of a group of sheets being bound and the other branch engages the bottom sheet. The two branches are relatively close to one another and are joined by a relatively short juncture portion, which is generally a semi-circular loop having a relatively small radius of curvature. The small distance of separation between the branches and the small size of the juncture loop results in a concentrated area of bending along the juncture loop, which is subject to high torsion forces distributed along its relatively short length. When the conventional paper clip is applied to a thick group of sheets, the elastic limit of the wire from which the paper clip has been made is exceeded, which causes it be permanently deformed and to thereafter exert very little binding force on the group of sheets to which it is applied. Another deficiency of previously known paper clips results from the fact that the wire material from which they are made is of circular cross section. There is only line contact between the branches and the sheets that the branches engage, which in turn results in relatively low frictional force. In addition, the ends of the round wire at the region of line contact produce sharp and pointed edges that can easily mar or tear the paper upon removal of the clip.
Previously known clips, which are generally applied to a part of the corner of a stack of paper sheets, necessarily occupy a considerable amount of space if they are to have a sufficient grip on the stack. If they are placed very close to the edge of the stack, it is easy to dislodge them as pages are turned back to allow examination of the contents of the same. Therefore, it is relatively inconvenient to bind the sheets of paper with previously known paper clips, owing to the fact that the clip must often be situated in the corner over a part of the text which is contained on the pages in order to achieve a secure engagement between the paper clip and the paper.